. >> when you talk about what are you going to do about coastal cities, what sort of defenses will you put in place if you want to have a city like manhan that's right on the coast, it's at sea level. can we not have that many people living close to the sea. we have almost 4 million americans living a if few feet of high tide. is it right to be insuring that kind of property as well. we also have to think about climate change. we can argue endlessly really and scientists do over exactly how much climate change plays what role with weather. but we know enough to take steps to deal with it. we know enough to have a plan in place to reduce carbon emissions over time. we don't have absolute certainly in foreign policy and the economy, we can't wait around until we know for certain we need to take steps now. >> rose: that's what the mayorpoind to, carbon attacks or maybe able to measure carbon standards. where is there a model, steve, of a city in the world that's responded to the challenge? >> well, it depends on how much wealth you have. i mean holland, the netherlands is essentially an e